Lighting apparatus



E. A. HAWTHORNE.

LIGHTING APPARATUS. APPLICATION FILED MAR. I0. 1917.

Patented Feb. 15, 19211.,

by g g I.

' i lTEl) ST LIGHTING APPATUS.

Specification of Letters Patent.

Patented Feb. 15-, 1921.

Application filed March 10, 1917. Serial No. 153,978.

To all whom it may concern:

Be it known that I, ELLSWORTH A. HAW- THORNE, a citizen of the United States, and a resident ofv Bridgeport, county of Fairfield, and State of Connecticut, have invented an Improvement in Lighting Apparatus, of which the following description, in connection with the accompanying drawings, is aspecification, like characters on the drawings representing like parts.

This invention relates to lighting apparatus, and is more especially, though not exclusively, concerned with an electric lamp of the search light type, in which a parabolic or other suitable concave reflector is associated with the electric lamp bulb, there being provided mechanism 'for focusinglthe latterwith relation to the reflector.

invention will be best understood by reference to the following description, when taken in connection with the accompanying drawings of one illustrative embodiment thereof, while its scope will be more particularly pointed out in the appended claims.

In the drawings: Figure 1 is a'central, vertical, sectional view of a lighting apparatus embodying my invention;

Fig. 2 is a detail plan of the lamp and its focusing mechanism; and r Fig. 3 is a detail, side elevation of some of the parts shown in Fig. 2.

Referring to the drawings, and to the embodiment of my invention which I have selected for illustration, I have there shown a lighting apparatus comprising a suitable li htsource 4, herein an'incandescent electrlc bulb associated with an appropriate reflector 5, the latter in the present instance being of the well-known parabolic type. The lamp bulb 4 and its reflector 5 may be, and are herein, mounted within a suitable casing 6 providing a. chamber 7 at the rear of'the reflector. I y

The lamp bulb 4 may. have a base or any suitable type, but that which is herein se lected for illustration is whatlisknown as thefEdis'wan base, comprising .a'metallic shell 8 provided with two laterally project'- ing pins 9 adapted for engagement with usual bayonet slots 10 formed In a suitable lam socket 11. These lamps are commonly ma e in two types, one'intended for a twowiresystem and the other for a single wire system, in which one of the lamp terminals secured to the reflector.

is grounded upon the metallic parts of the lamp casing. The latter of these types is here n shown for the sake of illustration, and 1s prov ded w th a central terminal 12. The'metalllc shell 8 constitutes the other lamp terminal.

Into the rear end of the lamp socket 11 is tightly fitted a connector plug 13, having an enlarged portion 14 which extends beyond the rear end of the lamp socket to provide for the attachment thereto of the usual lead wire or w res. In the present instance, a single lead wire'15 extends into the plug, and 1sconnected in a well-known manner, wh ch it will be unnecessary here to de-v scrlbe, with a common form of springpressed plug terminal 16, which engages the central terminal 12 of the lamp, and

constantly tends to urge the latter in a forward direction and maintain its pins 9 seated in the, bayonet slots 10.

' In order to provide for the necessary focusing of the lamp bulb 4 with relation to the reflector 5, the latter is herein provided with a rearwardly-extending neck 17 which in the present instance is in the form of. a ferrule soldered or otherwise appropriately Within this neck or ferrule, the lamp socket 11 is mounted to move axially. To produce this axial movement, I have provided focusing mechanisnfcgmprising a rotatable actuating member 178, located externally of the lamp casing ataconven'ient point where itmay be grasped by the user. The rotary motion of thgmember 18 may be translated into rectilinear movementof the lamp by suitable mealts, herein a screw 19 attached to the member 18 and having screw-threaded engagement with a nut 20, the latter herein forming a part of a yoke 21 provided with a pair of arms 22 suitably secured to the lampsocket 11.

In the present example, the yoke arms 22 are secured to the lamp socket 11 by providing the latter with lateral. perforations 23 to. receive said arms, the latter extending through said-perforations and being clenched over onto the inner' side of' the socket, as clearly shown in- Fig. 1,'thus securely uniting the yoke and the lamp socket of connecting the lead wire or wires to the plu 13. Moreover, the latter may be convenlently unfastened and then moved in a rearward direction to withdraw it from the socket, whereupon the plug may be withdrawn in a lateral directionfrom between the arms 22 for purposes of inspection, repair or replacement.

As a means for holding the. yoke against rotation and enforcing a forward and backward movement of the lamp bulb when the screw 19 is turned, I have provided the socket 11 with a pair of slots 24 to serve as guideways for the arms 22, which have a sliding fit therein. Thus when the screw 19 is turned in the proper direction, the lamp bulb will be carried forward or backward, as the case may be, and properly adjusted with relation to the reflector 5.

The screw 19 may be held against axial movement by an appropriate means, but herein it is provided with a reduced 01'- tion 25 passing through and journale in the rear end of the lamp casing 6, and a shoulder 26 engaging the interior of the lamp casing and preventing outward movement of the screw with relation thereto. Inward movement is prevented by the member 18, which bears against the outer surface of the lamp casing. In the present example, this member 18 is in the form of a' hollow shell having an inwardly directed flange 27 encircling a reduced portion 28 of the screw 19 and bearing against a shoulder' formed by such reduced portion. The flange is clamped'against this shoulder by the head of a screw 29 which is threaded centrally into the screw 19; Thus the .member 18 constitutes a convenient handle for turning the screw 19 to effect the focusing of the lamp bulb, and if desired, said handle may be knurled as shown in Figs. 2 and 3 to provide a non-slipping surface for the fin ers of the user.

ince the lamp bulb herein shown is of the single wire type, its terminal 8 is grounded upon'the metallic socket 11, the latter in turn is grounded upon the metallic neck or ferrule 17, and the ferrule is ground ed upon the metallic reflector 5, which in turn is in electric connection with the metalhe casing 6. Any suitable switching means may be provided, as for example a switch 30, which it will be unnecessary here to describe, since. the latter forms no essential part of my present invention, it being understood, however, that the switch is suitably connectedwith the lamp casing, and with theflead wire 15.

While I have herein showiipand described one s ecific embodiment of my invention for 11 ustrative purposes, and have d sneeepaa closed and discussed in detail the construc- .tion and arrangement incidental to one specific application thereof, itis to be understood that the'invention is limited neither. .to the mere details or relative arrangement of parts, nor to its specific embodiment herein shown, but that extensively deviations from the illustrated form or embodiment of the invention may be made, without departing from the principles thereof. Having thus described one form of my invention, what I claim and desire by Letters Patent to procure is:

1. In a lighting apparatus, the combination of: a; lamp, a concave reflector associated therewith, a lamp socket provided with a.

pair of perforations, and mechanism for focusing said lamp wlth relation to said reflector, sa1d mechanism comprlslng a coaxially disposed rotatable actuating member,

and means for translating rotary motion of and means for translating rotary motion of said member into rectilinear movement of said lamp, said means including a yoke having a .pair of arms extending lengthwise of the axis v and transversely thereof through said perforations and clenched over onto the inside of said socket, and a member in which said arms are slidably and non-rotatably guided. 1

3. In a lighting apparatus, the combination of a lamp, a concave reflector associated therewith, a lamp socket provided with a pairof oppositel disposed perforations, and mechanism for ocusing said lamp'with relation to said reflector, said mechanism comprising a coaxially-disposed rotatable actuating screw, and means for translatingrotary motion of said screw into rectilinear movement of said lamp, said means including a yoke having a pair of arms extending lengthwise of the axis and having their ends bent transversely and entering and secured in said perforations andmeansrestraining rotary movement of said yoke and arms with said screw.

In testimony whereof, I have signed my name to this specification,

' ELLSWORTH A. HAWTHORNE.

said member-into rectilinear movement of 

